Aviatik 30.40

womenfly2 · 23 November 2008, 06:29 AM

I agree. The size of the cowling and forward fuselage dwarfs the tail, the illusion is it appears even smaller. As with any vintage airplane one always leads a turn with rudder, full size or model.

Glad to see you keep it all to scale, she will fly as did the original.

Looking forward to her birth. Hopefully at ORA too this coming year.

WF2

JohnFitz · 26 November 2008, 07:16 AM

WF2, I will try my best to make that happen! Happy Thanksgiving to all.

Doc Modeler · 29 November 2008, 07:30 AM

John, Doc here, the SE 5a is ready to fly and I'm just waiting on the right day. Lots of warm sunny ones but windy. If I may make a suggestion on glassing your fuse, use silk iinstead. Google Tai silks, click on fabrics then on Habotai China silk, scroll down to #021 Habotai 5mm 36". It' only 2.95 a yard. That's about 5 yards for the same cost as a yard of Sig Esaki Jap silk. I've done a seaplane and a pair of floats with this and it's a pleasure to work with. I brush some resin on to the work and place the silk - theres no fraying at the edges like glass and it just is easier to handle - and squeegee the resin throught the silk adding resin as required as I go toward the edges. Roll off the excess resin as requires wit the tp roll method and when cured you can forget about a second coat of resin. Avery light sand if needed and prime it. I told a friend about it and he put it on an ARC P-51, He bought me lunch the next time we got together and said he'd never use glass again. Just a suggestion, I know it's hard to try something new but if you do I think you'll be very satisfied with the results. Happy Hollidays. Doc.

JohnFitz · 29 November 2008, 08:27 AM

Hey Doc, Thanks for that. I am all about trying something new. I am trying not to add much weight. I'll think about your suggestion. Cheers.

JohnFitz · 29 November 2008, 08:34 AM

Here's the stab. done. Very simple construction. Laminated bass and balsa with CA and an 5/16 carbon arrow shaft. The original Aviatik D1 drawing is courtesy of Koloman Mayerhofer. It shows how the T/E and L/E of the stab. and elevator pass through the fuselage.

Doc Modeler · 29 November 2008, 09:00 AM

John, what's the thicknessand how many lams of bass/balsa. That looks like a prety tight curve. I laminate all my tips and tail part outlines, usually just balsa left to soak in an old fishing rod storage tube for 24 hrs or so, seldom using any ammonia. The addition of some bass would lend a lot of strength, I've not considered it because of the resistance to bending, even wet. Doc.

JohnFitz · 29 November 2008, 11:35 AM

Doc, I am using 1/16" bass and 1/8" hard balsa sheet which I cut to shape with a scroll saw then laminate using CA. The CA really firms it all up when it soaks in. The laminating idea really came from Dave Johnson.

Doc Modeler · 29 November 2008, 02:03 PM

I get, it you're using balsa bass balsa from bottom to top. I laminate from inside to outside balsa balsa balsa as thick as needed. I use 1/16 or 3/32 cut in strips and wrapped wet around a form with alphatic applied to each strip as it's applied and let the whole thing cure and dry for a couple of days. Makes a strong light tip bow or stab/fin rud outline. Your method would be best in tight radii situations as even wet there's only so much bend in a strip of balsa. Thanks Doc.

Olson · 29 November 2008, 03:24 PM

Doc, I also make laminated rudders, wing tips, etc using 1/16" wet balsa strips, but always add at least one lamination of 1/16" plywood to stiffen the final product. Usually the plywood is the innermost layer so that the balsa layers can be easily sanded to the proper rounded contour. On thick laminations (i.e. outer wing tip bow) of more than 3/8" thickness I usually add an additional plywood layer in the middle of the stack. Never had any trouble bending properly wetted laminations around pretty tight radius curves. Overnight soaking is a minimum, and I try to avoid using ammonia because I've read it weakens the fibres in the balsa. I also stick with good ol' Ambroid for laminating since it sands with about the same consistency of medium hard balsa.............John

Doc Modeler · 29 November 2008, 03:42 PM

John, thanks, never thought of strips of thin ply as an added reinforcement. It's in the memory bank. The tip bows on my 1/3 N 28 are about an inch in width, they're very strong but if I had it to do over I'd add a strip or two of ply, especially the lowers as I did away with the kit gear and built one to scale dimensions and it's narrower than the kit stuff putting the lower tips in some peril. Doc.